只需读取文件,然后通过 websocket 发送。

package main

import (
    "fmt"
    "net/http"
    "os"

    "golang.org/x/net/websocket"
)

func EchoServer(ws *websocket.Conn) {
    file,_ := os.ReadFile("a.txt")
    n,err := ws.Write(file)
    if err != nil {
        fmt.Println(err)
    }
    fmt.Println(n,"bytes written")
}

func main() {
    http.Handle("/ws",websocket.Handler(EchoServer))
    err := http.ListenAndServe(":12345",nil)
    if err != nil {
        panic("ListenAndServe: " + err.Error())
    }
}